School-based, family-centered interventions for reducing substance use in adolescence have been shown to be highly effective and result in reductions in problem behavior, achievement problems, depression, and substance use over time. Although these interventions have been shown to be effective in efficacy trials across the United States, few schools have the resources to implement these interventions without substantial support. Barriers such as low staffing, poorly trained staff, and limited resources prevent the successful uptake of family-centered interventions in schools, yet most school systems are supportive of enhancing family-school partnerships. The proposed study will build upon our successful program of research by developing and testing the efficacy of an online version of the Family Check-Up (FCU) for schools that parents can use either at the school or at home. The FCU-Online will incorporate the successful components of the original FCU, such as a strengths-based assessment that is norm referenced, feedback using motivational interviewing, and follow-up modules that focus on enhancing parenting skills and family management in early adolescence. In the proposed research, 300 families will be randomly assigned to receive middle school as usual, the FCU-Online web/mobile only, or the FCU-Online web/mobile+coach version. Research on the delivery of mental health interventions via the Internet suggests that a coach or in person contact enhances outcomes; however, programs that require no coaching or in-person contact may have a larger public health impact. A coach version of the intervention will be compared with an online-only version that requires no staffing at schools. We will test the efficacy of this online version with respect to changing key parenting constructs, such as positive parenting and parental monitoring. We predict that changes in parenting will lead to reductions in risk behavior, such as problem behavior at school and substance use. This research will significantly contribute to our understanding of effective interventions for adolescents that reduce risk behavior and substance use during the transition to high school, and it can significantly contribute to the overall uptake and dissemination of family- centered interventions in schools.